With development of wireless technologies, a remote radio unit (RRU) and a baseband unit (BBU) that are originally located on a same base station are separated from each other. Coverage of the RRU becomes smaller, and the RRU logically approaches a user. BBUs are pooled and virtualized, and are deployed together. A fronthaul (Fronthaul) manner is used on an RRU side and a BBU side.
Referring to FIG. 1, FIG. 1 is a structural diagram and a schematic diagram of deployment of a wireless network in the prior art. As shown in FIG. 1, each station includes only an RRU device, and all BBU devices move up to a centralized equipment room to form a BBU pool. A BBU and an RRU are connected by using a common public radio interface (CPRI) and an optical fiber. The BBU and the RRU transmit data to each other over the optical fiber by using a CPRI transfer protocol. Specifically, when the BBU or the RRU needs to transmit a radio signal, the BBU or the RRU encapsulates the radio signal in a CPRI protocol frame format, and transmits the encapsulated radio signal by using the CPRI interface and the optical fiber.
The foregoing network structure has the following disadvantages: Because the radio signal needs to be encapsulated according to the CPRI protocol, there is a relatively large amount of invalid data, and transmission efficiency is relatively low. In addition, a large quantity of optical fibers need to be deployed between the BBU and the RRU in the transmission manner.